Problem: Simplify the expression. $(3t^{4}+4t)(-7t^{4}-5t)$
Explanation: First use the distributive property. $ 3 t^4 (-7 t^4) + 3 t^4 (-5 t) + 4 t (-7 t^4) + 4 t (-5 t) $ Simplify. $ - 21t^{8} - 15t^{5} - 28t^{5} - 20t^{2} $ $-21t^{8}-43t^{5}-20t^{2}$ Identify like terms. $ {- 21t^{8}} {- 15t^{5}} {- 28t^{5}} {- 20t^{2}} $ Add the coefficients. $ { -21t^{8}} { -43t^{5}} { -20t^{2}} $